Switching device

ABSTRACT

Disclosed is a switch housing having a generally cylindrical shape. Cylindrically shaped magnetically permeable and electrically conductive end members or caps are joined to one another by a cylindrically shaped, electrical nonconductive, magnetically impermeable sleeve. The end members or caps and sleeve enclose a cylindrically shaped cavity. One end member or cap, within the cavity, has a substantially hemispheric depression. In registry with the cap hemispheric depression and movable relative thereto is the hemispheric depression of a magnetically responsive, cylindrically shaped, substantially electrically non-conductive armature. Communicating with the armature hemisphere and extending axially therefrom and within the armature is a frusto-conically shaped recess. A cylindrical aperture provides an opening from the frusto end of the cone to the end of the armature opposed to the hemispheric end. A first electrical contact is defined by the axially aligned end cap having the hemispheric recess therein. The recess may be selectively wetted to effect electrical contact with mercury disposed in the sphere defined by the armature and housing recesses. A second electrical contact is an integral part of the second end cap and includes an axially extending portion within the cavity which projects into the cylindrical aperture of the armature.

United States Patent [1 1 Rich et al.

[ SWITCHING DEVICE [75] Inventors: Donald S. Rich, Flanders; Norman Rudnick, Piscataway, both of NJ.

[73] Assignee: Inflo Systems, Inc., Chester, NJ. [22] Filed: June 7, 1974 [21] Appl. No.: 477,430

Primary Examinerl-larold Broome Attorney, Agent, or FirmPhilip Furgang [57] ABSTRACT Disclosed is a switch housing having a generally cylindrical shape. Cylindrically shaped magnetically permeable and electrically conductive end members or caps IA. Q

[451 Sept. 9, 1975 are joined to one another by a cylindrically shaped, electrical nonconductive, magnetically impermeable sleeve. The end members or caps and sleeve enclose a cylindrically shaped cavity. One end member or cap, within the cavity, has a substantially hemispheric depression. in registry with the cap hemispheric depression and movable .relative thereto is the hemispheric depression of a magnetically responsive, cylindrically shaped, substantially electrically non-conductive armature. Corn'municating with the armature hemisphere and ei'rtending axially therefrom and within the armature is a frusto-conically shaped recess. A cylindrical aperture provides an opening from the frusto end of the cone to the end of the armature opposed to the hemispheric end. A first electrical contact is defined by the axially aligned end cap having the hemispheric recess therein. The recess may be selectively wetted to effect electrical contact with mercury disposed in the sphere defined by the armature and housing recesses.

A second electrical contact is an integral part of the second end cap and includes an axially extending portion within the cavity which projects into the cylindrical aperture of the armature.

29 Claims, 6 Drawing Figures PATENI EU 9i975 3,904,999

SHEET 1 [1F 2 nd w I! I a If I I 4" r 1''! 4.! I If A x Q k a p Q l v 7 A I? II I! I4, ll mm g PAIENTED 9W5 3,904,999

sum 2 BF 2 FIG. 3

FIG. 5

SWITCHING DEVICE BACKGROUND OF THE INVENTION This invention relates to switches and, more particularly, electrical switches employing a liquid conductor.

Electrical switches employing a liquid conductor as a throw are well known. A discussion of prior art of liquid conduuctive switches will be found in copending applications for United States Letters Patent for SWITCHES, Ser. No. 345,358 by Donald S. Rich, filed Mar. 27, 1973; and for SWITCH MECHANISMS, Ser. No. 474,038 by Donald S. Rich and Norman Rudnick and filed May 28, 1974, both assigned to the same assignee as herein.

It will be understood that the invention herein represents an improvement as comparecl with the prior devices disclosed by Schmid in US. Pat. No. 3,358,109; Lanctot in US. Pat. No. 3,184,693, and Ubukata et al. in US. Pat. No. 3,377,445. A more complete discussion of the devices disclosed in these US. patents and their deficiencies will be found in the aforementioned applications for United States Letters Patent and is included herein by reference.

Thus, the prior art devices exhibit certain disadvantages. The flow of mercury or any other liquid conductor is achieved only at the expense of either being position-sensitive (Lanctot and Ubukata et al.) or work against gases compressed by the flow of the liquid conductor (Schmid and Lanctot).

Of additional interest is the device disclosed by Lowry in US. Pat. No. 3,673,524. In that device, a piston is in the form of a donut and is movable within a cavity. Mercury in the cavity is channeledfrom one end of the cavity to the other through the hole in the donut. Thus, the donut acts as a conduit for the mercury rather than as a chamber to receive the mercury.

None of the prior art devices discloses a configuration in which contacts may be aligned along an axis of the housing. Thus, the prior art switch devices may not be conveniently disposed for use as a relay or other switch in which the contacts are axially aligned.

The spacing of contacts along an axis makes for greater distances and thereby reduces the effect of arcing. Thus, in relays of the reed type, the contact spacing for a given voltage and current load is often critical and arcing serves to wear the contact point. Thus, it becomes desirable to seek a maximum amount of spacing between contact. In reed type relays, this is often inhibited since the contacts are spaced radially rather than axially spaced (although the contacts do extend axially).

SUMMARY OF THE INVENTION An object of this invention is to provide a liquid conductive switch which will operate and be substantially insensitive to the forces of shock and vibration and orientation.

It is another object of this invention to provide a switch which exhibits bounce-free characteristics.

It is another object of this invention to provide liquid conductive switch which efficiently employs a minimum number of parts, is economic to manufacture, and simple and efficient in use.

It is still another object of this invention to provide a liquid conductive switch in which the conductors may be conveniently aligned and spaced along an axis for use as in a relay.

In accordance with the teachings of this invention, there is provided a housing having a cavity therein. An armature is within the cavity and movable relative to the housing. The armature and the walls of the cavity define a chamber in the cavity. The chamber comprises a first and second part. A liquid conductor is substantially within the first part. The first part is joined to the second part by a common port. The volume of the first part is dependent upon the relative position of the armature means such that with the armature in a first position, the liquid conductor is retained substantially within the first part of the chamber. The armature in a second position displaces at least a part of the liquid conductor from the first part into the second part of the chamber. The port between the parts of the chamber is dimensioned such that with the armature means being in the first position, the volume of the first part and the surface tensions of the liquid conductor result in the liquid conductor being retained in the first part. Displaced liquid conductor passes through the port. The first part is defined by walls including walls of the housing and armature. The second part is defined by walls of the armature exclusive of the housing walls. There are provided at least two electrical contacts communicating with the chamber from without the housing. The armature means in at least one of the respective positions within the housing causes the liquid conductor to couple the contacts and in another of the respective position of the armature means, the liquid conductor does not couple the contacts. Finally, there is provided means for moving the armature means with respect to the housing.

In another aspect of this invention, there is provided an armature means within the cavity of a housing. The housing has a principal axis extending along the length thereof. The liquid conductor is found within the chamber defined by the armature and the walls of the housing. The chamber is in two parts joined by a common port through which the liquid conductor may pass between the first and second part in dependence upon the position of the armature. There are at least two electrical contacts communicating with the chamber from without of the housing. The electrical contacts are disposed along an axis. This axis is at least in parallel with the principal axis of the housing. The armature means of at least one of the respective positions causes the liquid conductor to couple the contacts and in another respective position of the armature, the liquid conductor does not couple the contacts. There is also provided means for moving the armature means with respect to the housing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 6 is' a front plan view of the armature of FIG. 5 taken along lines 66.

DESCRIPTION OF THE PREFERRED EMBODIMENTS housing 12 has a preferably cylindrical shape. I-Iowever, the housing 12 may take any other elongated, rod-like shape such as that having a rectangular, elliptical, or other cross section.

The housing 12 may comprise two opposed end members 14 and 16. Each end member 14 and 16 define therebetween the axial length of a cavity 18 to be further defined hereinafter. It is to be understood that the switch mechanism of this invention may have any applicable use. As disclosed herein, one preferred use is that of a relay mechanism which is intended to be magnetically responsive. As is well known in relay devices, the housing ends 14 and 16 may be made of any magnetically responsive material, such as electromagnetic steel or the like, to provide a low reluctance path for the flux generated for the operation of the relay. In addition, the housing ends 14 and 16 may also serve as electrical contacts, as will be more fully discussed hereinafter. Thus, the ends 14 and 16 may be electrically conductive. In the alternative, the end members 14 and 16 may be insulated from the electrical contacts which pass therethrough into the cavity. The end members 14 and 16 may be each defined by cylindrically shaped body portions 20 and 22, respectively. Extending from planar, radially extending ends and 17 of the body portion and 22 may be smaller diameter, cylindrically shaped electrical contact members 24 and 26, respectively. Clearly,

these contact members 24 and 26 may take any other convenient shape and may, in the alternative, be the exposed ends of contacts insulated from the body portion 20 and 22. These contacts 24 and 26 extend in opposite directions from one another and are intended to be Each cavity housing portion 28 and 30, which may preferably form an integral part of the body portions 20 and 22, respectively, may be generally cylindrical in shape, extend coaxially therewith, and have a smaller diameter than the body portions 20 and 22. As previously indicated, the cavity housing portions 28 and 30 may have any convenient shape. The first of the cavity housing portions 28 may, as indicated, be cylindrical in shape and extend coaxially from the body portion 20 of the first end member 14. In the exposed, planar, radiallyiextending end 31 of the body portion 20, may be a depression 32 (FIG. 3)..The depression 32 may be, for example, a segment of a sphere. Preferably, this segment 32 may approach but be less than a hemisphere (hereinafter referred to as a hemisphere). The other cavity housing part 30 of the second end member 16 may also comprise a substantially cylindrical member extending coaxially from the second body portion 22 and terminate in a planar radially extending end 34. Extending from that radial end 34 may be a smaller, wirelike axially aligned stub 36. The wire stub 36 of the sec- 0nd end member 16 is opposite the hemispheric end 32 and spaced therefrom by a cylindrical sleeve 38. This stub 36 serves as a second electrical contact. A cylindrical sleeve 38 may be so dimensioned as to fit snugly about the cavity parts 28 and 30 and space them from one another. The sleeve 38 may be so dimensioned so that the inner diameter thereof fits snugly about and may be secured to the housing portions 28 and 30. The

sleeve 38 preferably has a low magnetic permeability. The sleeve 38 can be electrically nonconductive. In such an instance, it may be made of glass, plastic, or the like and be secured to the steel body portion 28 and 30 in a manner well known in the art. If good heat dissipation is desired, the sleeve 38 may be an electrical conductor and insulated at least from one of the end members 12 or 14.

Within the sleeve 38 and between depression 32 of the first body part 28 and the radially extending wall 34 and its axially projecting stub 36 of the second body part 30 may be a substantially cylindrically shaped cavity 18. Within the cavity 18 and movable with respect to the housing 12, is an armature 42 (FIGS. 1, 2, 5, and 6). The armature 42 may have a generally cylindrical configuration (or any other shape which conforms to the shape of the cavity 18) with the principal axis of the cylinder thereof coaxially aligned with the axis of the body parts 20 and 22.

A radial extending end 44 of the armature 42 faces the hemispheric end 32 of the first body part 28 and has formed therein depression 46 which may take the form of, for example, a segment of the sphere. Preferably, this segment 46 may be approximately a hemisphere of substantially the same configuration as the hemisphere 32 in the cavity housing part 28. The armature hemisphere 46 may be intersected by a frusto-conically shaped depression 48. The base of the cone 48 intersects the hemisphere 46 forming a port 50 which may be substantially perpendicular to the axis of the housing 12. The orientation of the cone 48 and intersection or port 50 is not considered significant. The port 50 and cylindrical armature 42 having an axially extending opening therethrough which may be defined, proceeding axially, as a hemisphere 46 communicating with a frusto cone 48 joined to a cylindrical aperture 54. The

end 56 of the armature 48 having the aperture 54 42 may be preferably made of a plastic or other electrical insulator while the exterior thereof may comprise a cylindrical collar 66 of a magnetically responsive matethe hemispherical rial such as steel. In this respect, the exterior configuration of the armature 42 is similar to the armatures of the aforementioned application by Donald S. Rich and Norman Rudnick.

A liquid conductor 58 (FIGS. 1 and 2) is disposed within the cavity 18. More particularly, the armature 42 is withdrawn to a first quiescent position, such that its radial end 56 abuts the radial end 34 of the cavity housing part 30 so that the substantially hemispheric depressions 32 and 46, together with the space therebetween, define a sphere. The liquid conductor, which may be, for example, mercury 58, is placed within the sphere so as to completely or substantially till the sphere (FIG. 1).

It will be observed that the armature 42 has in the cylindrical side flattened portions 62 (FIG. 6). The purpose of the flats 62 in the cylindrical side of the arrnature 42 will be more fully discussed hereinafter.

The armature 42 may be made of a magnetically responsive material. Thus, as previously indicated, the armature 42 may comprise a plastic body portion 64 enclosed by the collar or shell of a magnetically respon sive material such as steel 66. As previously indicated, the end body portions 20 and 22, as well as the cavity housing parts 28 and 30, may be made of a magnetically responsive material such as, for example, steel. An insulating film 68 may be disposed on the radial planar end surface 34 of the housing cavity part 30, which has the stub 36 extending therefrom. The function of the insulating film 68 will be more fully discussed hereinafter.

In operation, it will be observed that the armature 42 will move toward the hemispheric depression 32, thereby decreasing the volume of that first part of a chamber defined by the hemispheric depressions 32 and 42 and cone 48. The mercury 58 within the sphere is displaced into the frusto-conical portion 48. It should be observed that the port 50 which substantially defines the intersection between the frusto cone 48 and the hemispheric depression 46 of the armature 42 is so dimensioned such that with the armature 42 fully withdrawn to the first position, the surface tension of the mercury 58 is great enough to prevent the mercury 58 from entering into the conical portion 48. With the mercury displaced by the armature 42 into the cone 48, the walls act upon the displaced mercury 58 so that upon moving the armature 42 from its second quiescent position (FIG. 2) to the first position (FIG. 1), the displaced mercury 58 returns to the main pool of mercury 58 in the spherical part of the chamber. The principles involved are those as more fully discussed in the aforementioned applications for United States Letters Patent by Rich and Rich and Rudn'ick. The substantially hemispheric portions 32 and 46 come together reducing the overall volume, and the armature 42 overcomes the surface tension of the mercury 58.

It is noteworthy that differing from prior art devices, the portion of the switch which receives the dis placed mercury 58 is solely within the armature 42.

The displaced mercury 58 is thus not confined either solely in a housing or between an armature and a wall of the housing. As a result, there is derived a significant saving of space and improved symmetry, thereby simplifying the shape of the various components and permittin g a significant reduction in space. This is a significant difference from prior art devices.

Still another difference is that the electrical conductors are disposed along an axis. The stub 36 is one of the electrical contacts; the base hemispheric depression 32 in the cavity housing part 28 is the other contact. Thus, when the mercury 58 is displaced by the armature 42, electrical contact is made in an axial direction. In order to insure complete electrical contact, a portion of the hemispheric depression 32 inthe cavity housing portion 28 and the stub 36 may be wetted.

Venting of the gases and the recirculation of any mercury droplets within the cavity 18 may be accomplished by permitting the gas to move freely between the stub 36 and cylindrical aperture 54. Mercury droplets that enter'bet'ween the contact 36 and the aperture 54 may be recirculated by passing between the radial ends 56 and 34 and recirculate through the flats 62 of the armature 42 to the spherical part of the chamber, thereby forming a complete system.

It is essential that the mercury 58 not be permitted to prematurely short the switch 10. Thus, as previously indicated, the armature 42 should be electrically nonconductive, while being magnetically responsive. An alternative to the preferred magnetically responsive sleeve 64 and electrically nonconductive body 62 may be an electrical insulated ceramic of high magnetic permeability.

The insulating of the surface 34 of the cavity housing 30 with film 68 is intended to insure against premature shorting by any mercury lodged therein that had passed between the cylindrical portion 54 and stub 36 to between the armature 42 and the end portion 30.

The hemispherical ends 32 and 46 form a sucking effeet as discussed in the aforementioned application by Rich and Rudnick which adds to the recirculatory effect. It should be further understood that channels for venting gases may be disposed in the frusto-conical portion 48.

It should be observed that the electrical contacts 32 and 36 of this switch 10 are axially disposed making this device suitable for use as a relay. On the other hand, the coil might be replaced by a toroidal magnet (not shown) for moving the armature 42 from one position to another, as with a push button.

A comparison between the device disclosed herein and the well known reed relay is instructive. Here it will be observed that the distance from the first contact 36 to the second contact 32 (which may also comprise the pool of mercury 58) is (in FIG. 1) a substantially larger distance than it would be for an equivalently dimensioned reed relay where contacts are spaced radially. Thus, there is a longer are distance between contacts. Reed relays very often require an inert gas under high pressure to reduce the arcing between such contacts. For the same configuration, voltages and current, it is clear that a lesser gas pressure will be required for the switch 10. Further, because of the separation of the contacts, the deletorious effect of arcing is substantially reduced. In addition, the narrowing passageway between the hemisphere and into the conical section 48 of the armature 42 creates a hydraulic working advantage. Thus, for small movements of the armature, the mercury volume is displaced a long distance, thereby providing an operational working advantage. The principles of operation including the displacement of the mercury into the conical section 48 and the removal therefrom, have been more fully discussed in connection with the aforementioned applications by Rich and Rich and Rudnick and the applicable portions are included herein by reference,

What is claimed is: 1. A switch comprising: a. housing means having a cavity therein; b. an electrically conductive liquid within said cavity; 0. an armature means within said cavity and movable relative to said housing; said armature means and said housing defining within said cavity a chamber; said chamber comprises at least a first and second part; said first part of said chamber being joined to said second part at a'common port; the volume of said first part of said chamber being dependent upon said relative position of said armature means such that with said armature means in a first position, said liquid conductor is retained substantially within said first part of said chamber; with said armature means being at least in a second position, said armature means displaces at least a part of said liquid conductor from said first part into said second part of said chamber; said port being so dimensioned such that, with said armature means being in said first position, said volume of said first part in combination with the forces of surface tension upon said liquid conductor and the volume of said liquid conductor within said first part, thereby resulting in said liquid conductor being retained substantially in said first part; upon said armature means moving relative to said housing to and from said second position, said port admitting said displaced liquid conductor between said first and second parts of said chamber; said first part being defined by at least walls of said housing and said armature means; said second part comprises housing recess each being a segment of a sphere less than a hemisphere.

walls of said armature means exclusive of said housing; said armature means in at least one of said relative positions, causing said liquid conductor to couple said electrical contacts and, in another of said relative positions said liquid conductor not coupling said contacts; and

e. means for moving said armature means relative to said housing thereby coupling or uncoupling said contacts to operate said switch.

2. A switch as recited in claim 1, wherein said first part comprises said housing having a recess therein for receiving said liquid conductor.

3. A switch as recited in claim 2, wherein said armature means comprises a member having a first recess therein; said armature recess in combination with said housing recess and said housing walls define said first part.

4. A switch as recited in claim 3, wherein said armature means further comprises a second recess in com munication with said first recess, said communication being defined by said port, said second recess comprises said second part of said chamber.

5. A switch as recited in claim 4, wherein said first recess in said armature member and said housing means recess define, with said armature in said first position, a sphere; said armature member first recess and said 6. A switch as recited in claim 5, wherein said armature member second recess is defined by walls lying in at least three intersecting planes; said port being opposed to the apex formed by said intersecting planes.

7. A switch as recited in claim 6, wherein said second electrical contact extending from said housing and into said second part of said chamber and said armature member moves relative to said first and second contacts.

8, A switch as recited in claim 7, further comprises a gas within said cavity; said armature means having an aperture communicating with said second recess and said cavity; said second contact passing freely through said aperture so as to come into electrical contact with said liquid conductor with said armature means being in said second position; said second contact and said aperture defining therebetween a space of sufficiently small cross-sectional dimension as to inhibit the flow of said liquid conductor and to pass therebetween said gas so as to vent said chamber of said gas as said liquid conductor moves into and out of said second part.

9. A switch as recited in claim 8, wherein said armature means in combination with said housing defines therebetween a passageway between said armature means aperture and said first part of said chamber to recirculate any of said liquid conductor passing between said second electrical contact and said aperture, out of said chamber, and within said cavity.

10. A switch as recited in claim 9, wherein said armature means second recess is substantially frustoconically shaped, said aperture being substantially cylindrically shaped and extending from the frusto end of said cone, said second contact being substantially cyiindrically' shaped.

iii. A switch as recited in claim 10, wherein said housing cavity is substantially rod-shaped and said armature means relative movement being coaxial with the principal axis of said housing; said means for moving said armature means relative to said housing comprises magnetic means; said armature means comprises magnetically responsive means.

12.A switch as recited in claim ill, wherein said housing comprises a hollow cylindrical body, closed at opposed ends by first and second radially extending planar walls, said cavity being substantially cylindrically shaped, said armature means being substantially cylindrically shaped and complementing the cylindrical walls of said housing defining said housing cavity; said portion comprises said passageway; said armature havresponsive; said one contact extending axially from said second end surface; insulating means affixed to said second planar end surface of said housing so as to inhibit electrical contact between said armature and said housing end.

14. A switch as recited in claim 13, wherein said housing ends comprise first and second end members and a cylindrical nonmagnetic,magnetically impermeable sleeve member; said first housing end member being electrically conductive; said first electrical contact comprises said first end member thereby forming an axially extending electrical contact.

15. A switch as recited in claim 14, wherein at least a portion of said hemispheric base recess being wettable by said liquid conductor, thereby comprising a part of said first electrical contact, said second contact being wettable by said liquid conductor.

16. A switch as recited in claim 15, wherein said sleeve member is an electrically conductive material affixed to said end members and electrically insulated from at least one of said end members. i

17. A switch as recited in claim 16, wherein said sleeve member is electrically nonconductive material and affixed to said end members.

18. A switch as recited in claim 15, wherein said second contact comprises an integral part of said second end member.

19. A switch as recited in claim 18, wherein said first and second end members each comprise first exterior electrical contact portions of electrically conductive material and having a cylindrical shape and a second, larger diameter axially aligned electrically conductive cylindrically shaped body portion; one of said body portions having extending therefrom a cylindrically shaped axial extension terminating in said hemispheric recess end; the other of said body portions having extending therefrom a cylindrically shaped axial extension terminating in said second contact; said sleeve having an inner diameter sufficient to envelope said extensions and be secured thereto to form in combination therewith said housing; said sleeve having an outer diameter equal to the diameter of said body part outer diameters; said liquid conductor is mercury; said magnetic means is a coil.

20. A switch comprising:

a. a housing having a cavity therein and defined at least by a principal axis extending substantially the length thereof;

b. an electrical conductive liquid within said cavity;

c. armature means within said cavity and'movable relative thereto;

said armature means and said housing defining within said cavity a chamber;

said chamber comprises a first and second part;

said first part of said chamber retaining therein said liquid conductor;

said first and second parts being conjoined at a common port; 7

said port being capable of permitting said liquid conductor to pass freely between said parts in dependence upon said relative position of said armature means;

d. at least a first and second electrical contacts communicating with said chamber from without said housing and disposed substantially along an axis, said axis being substantially parallel to said principal axis; said armature means in at least one of said respective positions, causing said liquid conductor to couple said contacts and in another of said relative positions of said armature means said liquid conductor not coupling said contacts; and e. means for moving said armature means relative to said housing thereby coupling and uncoupling said contacts so as to operate said switch.

21. A switch as recited in claim 20, wherein said housing cavity having rod-like shape.

22. A switch as recited in claim 21, wherein said first Contact communicates with said first part and said second contact communicates with said second part of said chaamber.

23. A switch as recited in claim 22, wherein said volume of said first part of said chamber being dependent upon said relative position of said armature means such that with said armature means in a first position, said liquid conductor being retained substantially within said first part of said chamber; with said armature means being at least in a second position, said armature means displaces at least a part of said liquid conductor from said first part into said second part of said chamber; said port being so dimensioned such that, with said armature means being in said first position, said volume of said first part in combination with the surface tension of said liquid conductor and the volume of said liquid conductor within said first part of said chamber, thereby resulting in said liquid conductor being retained substantially in said first part; and with said armature means moving relative to said housing to and from said second position, said port admitting said liquid conductor to between said first and second parts of v said chambers said movement of said displaced liquid conductor being substantially in a path along said parallel axis.

24. A switch as recited in claim 23, wherein said parallel axis being coincident with said principal axis and said principal axis defining the principal axis of said rod-like cavity.

25. A switch as recited in claim 24, wherein said first part comprises walls of said housing and said armature means and said second part comprises walls of said armature means exclusive of said housing walls.

26. A switch as recited in claim 25, wherein said first part of said chamber being defined by at least a recess within said housing and said second part being defined by a recess within said armature means; said second contact being in communication with said second part such that upon said armature means displacing at least a part of said liquid conductor into second part said contacts being coupled.

27. A switch as recited in claim 26, wherein said first and second contact ends are spaced axially from one another.

28. A switch as recited in claim 27, wherein said ar-;

said first part of said chamber.

29. A switch as recited in claim 28, wherein said housing cavity is substantially cylindrical, said armature means comprises a magnetically responsive member, cylindrical in shape complementing said cylindrical cavity; said means for moving said armature means comprises a coil about the exterior of said housing; said armature means moving in response to magnetic flux provided by said coil; said recess in said housing comprising a segment of a sphere substantially approximating a hemisphere, said armature having in a planar radially extending surface in registry with said housing hemisphere andhaving a recess therein of substantially and said aperture defining therebetween a space for venting said gas; said armature having in the cylindrical surface, axially extending flattened portions to form passageways for recirculation of liquid conductor between said aperture and said first part of said chamber; said housing cylindrical wall about said cavity being substantially nonmagnetic and at the opposed ends of said cavity, said housing walls being magnetically impermeable. 

1. A switch comprising: a. housing means having a cavity therein; b. an electrically conductive liquid within said cavity; c. an armature means within said cavity and movable relative to said housing; said armature means and said housing defining within said cavity a chamber; said chamber comprises at least a first and second part; said first part of said chamber being joined to said second part at a common port; the volume of said first part of said chamber being dependent upon said relative position of said armature means such that with said armature means in a first position, said liquid conductor is retained substantially within said first part of said chamber; with said armature means being at least in a second position, said armature means displaces at least a part of said liquid conductor from said first part into said second part of said chamber; said port being so dimensioned such that, with said armature means being in said first position, said volume of said first part in combination with the forces of surface tension upon said liquid conductor and the volume of said liquid conductor within said first part, thereby resulting in said liquid conductor being retained substantially in said first part; upon said armature means moving relative to said housing to and from said second position, said port admitting said displaced liquid conductor between said first and second parts of said chamber; said first part being defined by at least walls of said housing and said armature means; said second part comprises walls of said arMature means exclusive of said housing walls; d. at least first and second electrical contacts communicating with said chamber from without said housing; said armature means in at least one of said relative positions, causing said liquid conductor to couple said electrical contacts and, in another of said relative positions said liquid conductor not coupling said contacts; and e. means for moving said armature means relative to said housing thereby coupling or uncoupling said contacts to operate said switch.
 2. A switch as recited in claim 1, wherein said first part comprises said housing having a recess therein for receiving said liquid conductor.
 3. A switch as recited in claim 2, wherein said armature means comprises a member having a first recess therein; said armature recess in combination with said housing recess and said housing walls define said first part.
 4. A switch as recited in claim 3, wherein said armature means further comprises a second recess in communication with said first recess, said communication being defined by said port, said second recess comprises said second part of said chamber.
 5. A switch as recited in claim 4, wherein said first recess in said armature member and said housing means recess define, with said armature in said first position, a sphere; said armature member first recess and said housing recess each being a segment of a sphere less than a hemisphere.
 6. A switch as recited in claim 5, wherein said armature member second recess is defined by walls lying in at least three intersecting planes; said port being opposed to the apex formed by said intersecting planes.
 7. A switch as recited in claim 6, wherein said second electrical contact extending from said housing and into said second part of said chamber and said armature member moves relative to said first and second contacts.
 8. A switch as recited in claim 7, further comprises a gas within said cavity; said armature means having an aperture communicating with said second recess and said cavity; said second contact passing freely through said aperture so as to come into electrical contact with said liquid conductor with said armature means being in said second position; said second contact and said aperture defining therebetween a space of sufficiently small cross-sectional dimension as to inhibit the flow of said liquid conductor and to pass therebetween said gas so as to vent said chamber of said gas as said liquid conductor moves into and out of said second part.
 9. A switch as recited in claim 8, wherein said armature means in combination with said housing defines therebetween a passageway between said armature means aperture and said first part of said chamber to recirculate any of said liquid conductor passing between said second electrical contact and said aperture, out of said chamber, and within said cavity.
 10. A switch as recited in claim 9, wherein said armature means second recess is substantially frusto-conically shaped, said aperture being substantially cylindrically shaped and extending from the frusto end of said cone, said second contact being substantially cylindrically shaped.
 11. A switch as recited in claim 10, wherein said housing cavity is substantially rod-shaped and said armature means relative movement being coaxial with the principal axis of said housing; said means for moving said armature means relative to said housing comprises magnetic means; said armature means comprises magnetically responsive means.
 12. A switch as recited in claim 11, wherein said housing comprises a hollow cylindrical body, closed at opposed ends by first and second radially extending planar walls, said cavity being substantially cylindrically shaped, said armature means being substantially cylindrically shaped and complementing the cylindrical walls of said housing defining said housing cavity; said housing hemispherical recess residing in said first planar radially extending end of said cavity; said hemispherical recess of said armatuRe being within a planar and radially extending end of said armature; said frusto-conical recess and cylindrical aperture extending axially from said armature hemisphere.
 13. A switch as recited in claim 12, wherein said armature member comprises a magnetically responsive cylindrical sleeve enclosing an electrically non-conductive body portion; said armature having flattened portions along the length thereof; said flattened portion comprises said passageway; said armature having a planar radially extending end opposed to said end having said hemisphere therein; said planar end of said armature abutting said second planar end surface of said housing with said armature in said first position; said ends of said cylindrical housing being magnetically responsive; said one contact extending axially from said second end surface; insulating means affixed to said second planar end surface of said housing so as to inhibit electrical contact between said armature and said housing end.
 14. A switch as recited in claim 13, wherein said housing ends comprise first and second end members and a cylindrical nonmagnetic, magnetically impermeable sleeve member; said first housing end member being electrically conductive; said first electrical contact comprises said first end member thereby forming an axially extending electrical contact.
 15. A switch as recited in claim 14, wherein at least a portion of said hemispheric base recess being wettable by said liquid conductor, thereby comprising a part of said first electrical contact, said second contact being wettable by said liquid conductor.
 16. A switch as recited in claim 15, wherein said sleeve member is an electrically conductive material affixed to said end members and electrically insulated from at least one of said end members.
 17. A switch as recited in claim 16, wherein said sleeve member is electrically nonconductive material and affixed to said end members.
 18. A switch as recited in claim 15, wherein said second contact comprises an integral part of said second end member.
 19. A switch as recited in claim 18, wherein said first and second end members each comprise first exterior electrical contact portions of electrically conductive material and having a cylindrical shape and a second, larger diameter axially aligned electrically conductive cylindrically shaped body portion; one of said body portions having extending therefrom a cylindrically shaped axial extension terminating in said hemispheric recess end; the other of said body portions having extending therefrom a cylindrically shaped axial extension terminating in said second contact; said sleeve having an inner diameter sufficient to envelope said extensions and be secured thereto to form in combination therewith said housing; said sleeve having an outer diameter equal to the diameter of said body part outer diameters; said liquid conductor is mercury; said magnetic means is a coil.
 20. A switch comprising: a. a housing having a cavity therein and defined at least by a principal axis extending substantially the length thereof; b. an electrical conductive liquid within said cavity; c. armature means within said cavity and movable relative thereto; said armature means and said housing defining within said cavity a chamber; said chamber comprises a first and second part; said first part of said chamber retaining therein said liquid conductor; said first and second parts being conjoined at a common port; said port being capable of permitting said liquid conductor to pass freely between said parts in dependence upon said relative position of said armature means; d. at least a first and second electrical contacts communicating with said chamber from without said housing and disposed substantially along an axis, said axis being substantially parallel to said principal axis; said armature means in at least one of said respective positions, causing said liquid conductor to couple said contacts and in another of said rElative positions of said armature means said liquid conductor not coupling said contacts; and e. means for moving said armature means relative to said housing thereby coupling and uncoupling said contacts so as to operate said switch.
 21. A switch as recited in claim 20, wherein said housing cavity having rod-like shape.
 22. A switch as recited in claim 21, wherein said first contact communicates with said first part and said second contact communicates with said second part of said chaamber.
 23. A switch as recited in claim 22, wherein said volume of said first part of said chamber being dependent upon said relative position of said armature means such that with said armature means in a first position, said liquid conductor being retained substantially within said first part of said chamber; with said armature means being at least in a second position, said armature means displaces at least a part of said liquid conductor from said first part into said second part of said chamber; said port being so dimensioned such that, with said armature means being in said first position, said volume of said first part in combination with the surface tension of said liquid conductor and the volume of said liquid conductor within said first part of said chamber, thereby resulting in said liquid conductor being retained substantially in said first part; and with said armature means moving relative to said housing to and from said second position, said port admitting said liquid conductor to between said first and second parts of said chambers said movement of said displaced liquid conductor being substantially in a path along said parallel axis.
 24. A switch as recited in claim 23, wherein said parallel axis being coincident with said principal axis and said principal axis defining the principal axis of said rod-like cavity.
 25. A switch as recited in claim 24, wherein said first part comprises walls of said housing and said armature means and said second part comprises walls of said armature means exclusive of said housing walls.
 26. A switch as recited in claim 25, wherein said first part of said chamber being defined by at least a recess within said housing and said second part being defined by a recess within said armature means; said second contact being in communication with said second part such that upon said armature means displacing at least a part of said liquid conductor into second part said contacts being coupled.
 27. A switch as recited in claim 26, wherein said first and second contact ends are spaced axially from one another.
 28. A switch as recited in claim 27, wherein said armature means having a recess which in combination with said housing recess and said housing walls defines said first part of said chamber.
 29. A switch as recited in claim 28, wherein said housing cavity is substantially cylindrical, said armature means comprises a magnetically responsive member, cylindrical in shape complementing said cylindrical cavity; said means for moving said armature means comprises a coil about the exterior of said housing; said armature means moving in response to magnetic flux provided by said coil; said recess in said housing comprising a segment of a sphere substantially approximating a hemisphere, said armature having in a planar radially extending surface in registry with said housing hemisphere and having a recess therein of substantially the same dimensions as said hemisphere housing recess so that in said first position of said armature said hemisphere recesses in combination with a space therebetween define a sphere; said second part comprising a frusto-conical portion with the base thereof intersecting said armature hemisphere and a cylindrical aperture extending axially and receiving therein said second contact; a gas within said cavity; said second contact and said aperture defining therebetween a space for venting said gas; said armature having in the cylindrical surface, axially extending flattened portions to form passageways For recirculation of liquid conductor between said aperture and said first part of said chamber; said housing cylindrical wall about said cavity being substantially nonmagnetic and at the opposed ends of said cavity, said housing walls being magnetically impermeable. 